How to display one category per page for a particular category in WordPress (1 post)

I am fairly new to WordPress. I am developing a website with a custom theme (I am trying to learn by write one). The website is about automobiles and has categories as bikes, cars, copters etc. I have to display one of the categories (bikes) on the navigation menu. Now when I click on the this menu, it should take me to a separate page which display only the posts about the bikes category. And in this page, I want to display one post per page. So I made a category-8.php (8 being the id of bikes category). So I put the following code in there: